Normally you speak far enough over my head that I just sit back and absorb information at the feet of the Masters. Occasionally, I admit, I fall into an information-overload-induced coma – fortunately not while driving. Your episode involving the Wired article on rabies, however, fell well under my head as I had actually (and accidentally) read it the week before. I really wish that you had read the article more carefully because you stumbled over a number of important points.

There may have been some antivirals involved but I believe that the article mentioned the ketamine was the primary coma-inducing agent and was also believed to exhibit some anti-viral properties. I may have that a little off but it’s close.

More importantly, the coma was induced because of the observation that most of the neural damage was caused by over-stimulation of the neurons which, in turn, causes neural death. I believe that it is called excito-toxicity. The drugs used to generate the coma were chosen for their ability to decrease neural activity. The idea was to reduce neural activity long enough to allow the neurons to survive until the immune response kicked in.

Most importantly and related to the second point, the girl was not fine afterwards. She has had to go through months of physio-therapy just to be able to walk and talk again. A year afterward she is functioning well but will probably never be 100%. The coma-therapy probably did reduce neural death but it didn’t eliminate it. For this type of therapy to be more effective in the future and, thus, reduce recovery time (and, let’s face it, death), better neural receptor agonist will have to be selected, ones that more specifically target the excito-toxicity that rabies induces.

Anyway, you probably received a great many e-mails on the subject but, just in case this one proved helpful in some way, I thought that I had better send it. Thanks to all of you for the podcast and I look forward to the next 100.

Geoffrey

Marc writes:

I heard a recent TWIV episode this week in which it was mentioned that about twenty cases of Hand, Foot, and Mouth disease are confirmed in Canada per year. Including my 1 1/2 year old son’s case, I am aware of five cases affecting the very young that occurred in Houston, TX in May 2012. There have likely been many more cases in the area. To reduce the spread of this disease, it is important that parents isolate their children for two full weeks after they are back to feeling normal. My son, Holden, did not seem to be experiencing discomfort while eating but very cold fluids did help his appetite.

BTW, I have been listening to your show for a few weeks now on my Android phone using DoubleTwist Pro paired to Bluetooth headphones. I listen while playing with my son in the water for about an hour shortly before his bed time. Both my son and his several week old sister were home births facilitated by the well known nurse midwife Jackie Griggs.

It is too bad that the U.S. insurance companies will not cover what is the standard method for child birth in the Nordic countries. Over 1/3 of all U.S. hospital births result in Cesarean births with over 50% of induced hospital births resulting in Cesareans. In contrast, over 98% of all home births involving midwives do not require transport to a hospital. The U.S. lags behind many of the most prosperous countries in the world in limiting infant mortality rates and our medical system that incorporates some of the worst aspects of capitalist and socialist systems is a factor in the issue.

Enough ranting – please keep making science entertaining!

Robert writes:

Does this apply to any situations you have seen?

I shall begin, my friends, with the definition of a pseudoscience. A pseudoscience consists of a nomenclature, with a self-adjusting arrangement, by which all positive evidence, or such as favors its doctrines, is admitted, and all negative evidence, or such as tells against it, is excluded. It is invariably connected with some lucrative practical application. Its professors and practitioners are usually shrewd people; they are very serious with the public, but wink and laugh a good deal among themselves. The believing multitude consists of women of both sexes, feeble-minded inquirers, poetical optimists, people who always get cheated in buying horses, philanthropists who insist on hurrying up the millennium, and others of this class, with here and there a clergyman, less frequently a lawyer, very rarely a physician, and almost never a horse-jockey or a member of the detective police.

Oliver Wendell Holmes, Sr.

“Autocrat of the Breakfast Table” 1858

Hannah writes:

Dear TWiV Team,

Love your show. Keep up the great work. I was just listening to episode 192 and would like to second the request for a bioinformatics 101-type episode. You might consider getting someone(s) from the Broad Institute, specifically the Viral Genomics group on the show. (I’d highly recommend Matt Henn, though he appears to have just left his position as Director of Viral Genomics at the Broad, which might rule him out. I saw a talk by him and really enjoyed it; he’s a microbiology guy, and thus more understandable than some bioinformatics types.) I think that the Institute is a very neat model for scientific collaboration, particularly between more traditional scientists and computer geeks. I’d love to hear a discussion about how the Broad is set up, its advantages and disadvantages, etc as well as to get insight on the great bioinformatics work they do.

Greg writes:

Hi Guys,

My name is Greg, I’m an undergraduate at the University of Manchester, I’m a big fan of your Podcasts and over the last few months I have set up one of my own – The Life Sciences Podcast, it covers a range of things biological/medical related. As my podcast is in association with my University they’ve asked me to get some listener feedback, I was wondering if you’ve ever carried out a listener survey? Or have any advice on getting useful feedback from listeners?

Different animal species have different kinds of placenta (and different levels of interaction of fetal-maternal tissue/blood). Are trophoblast cells from other species also resistant to viral infection? Can the conditioned medium of human trophoblast cells interfere with animal viruses infection of human cells (or human viruses infection of animal cells)?

Tks!!!

[answer from Carolyn Coyne]

We have never directly tested non-human placentas for their infectivity or ability to transmit viral resistant to recipient cells (via conditioned medium). Presumably, many would have a similar mechanism(s) of resistance to those that we study in the human placenta. The cluster of placental-specific microRNAs that we have been studying (and which confer viral resistance) are specific to primates, but it is very possible (and perhaps likely) that other animals have specific miRNAs with similar functions. I will note that in vivo, the mouse placenta seems to be rather impermeable to most viruses (studies on mCMV rely on microinjection of the virus directly into the placenta), but there are not many studies that have investigated this question specifically.

In terms of animal viruses, we have not specifically tested these. However, given that the mechanism of viral resistance induced in recipient cells seems to be rather non-specific and far-reaching (autophagy primarily, but perhaps others), I would anticipate that many viruses of animal origin would also be susceptible to the antiviral effects of the placental conditioned medium.

Clyde writes:

Greetings from North Carolina,

I am a PhD student studying Norovirus in the Food Science department at NC State University. Norovirus as you probably know is a difficult virus to research in that there is no culture system available for it. I recently read a paper from a group at Baylor describing a new way to culture enteric viruses. The system works by creating a lab grown “intestinal epithelium” from stem cells. The paper shows that the concept works for Rotavirus. Perhaps this is a first step towards a functioning Norovirus culture system? I thought perhaps you would enjoy the read and maybe entertain the idea of discussing this on a future episode.